The reception of global positioning system (GPS) satellite position data may be problematic and may negatively impact the performance of GPS receiver. The conventional approach to using global positioning system (GPS) satellites to determine a receiver's position requires the receiver to download navigation messages from four or more visible satellites, extract the broadcast ephemerides for each satellite from the navigation messages, and utilize this ephemeris data to compute the position of the satellites in the ECEF (earth-centered earth-fixed) coordinate system at a specific time. The broadcast ephemerides for each satellite are provided in a frame of data that takes about 30 seconds to send/receive. The broadcast ephemerides are valid for a period of four hours starting from the time the satellite starts to broadcast the navigation data. A control station uploads the data to the satellite less frequently, usually a couple of times a day. After a four-hour period, the receiver has to again download the latest broadcast ephemerides.
It is desirable for a Wireless Local Access Network (WLAN) device to determine its location without the need for its own GPS receiver or in the absence of a GPS satellite signal. In addition, it is desirable to easily associate IP address of a WLAN device with its location.
For WLAN devices without a GPS capability, current methods of WLAN position locating rely on drive-by surveys of access points (APs) and/or user reporting of AP locations, which may be reported to a database in a central server. The database may be used to calculate the position of a mobile station (STA) from the RSSI and other information of visible APs in close proximity. The server generally does the calculation.
Current methods are generally expensive. The quality and reliability of the service may be a direct function of the frequency and density of the drive-by surveys and the reliability of individual user and/or crowd-source reporting. Additionally, current methods may be limited by the commercial access to the server (typically through an expensive tariff) and may be vulnerable to service outages due to loss of coupling to the server or loss of the server itself (e.g. due to financial insolvency of the server administrator).
Current methods may not directly enable the APs themselves to become self-aware of their own location. (A network device is location self-aware if it has the ability to self-determine its location.) And the current methods may not enable the APs to report/exchange their location to other APs or mobile STAs, or to lookup servers or web applications. (A lookup server may be referred to as a location server.) In addition, current methods may not enable association of the WLAN's IP address and location because drive-by surveys may not easily ascertain the IP address of APs and users typically do not know the current IP address on an instantaneous and continuous basis because IP addresses may be dynamic. Current methods lack AP self-reporting of location.
One current method for an AP to determine its location is for the AP to be equipped with a GPS receiver. Very few APs today may be so equipped because of the cost of GPS receivers and because of the inherent limitations of standard GPS, such as poor indoor coverage.
Additionally, although location systems in portable devices may be widely used, they are generally not secure so there may be concerns relative to the accuracy of such systems.
Thus, it may be beneficial to have a system and method to acquire and update the current location estimates in network devices. Specifically, it may be beneficial if network devices were location self-aware and the network devices may also share location information with other network devices. Further, these methods may benefit if the location information has a high level of security and trust.